Problem with pickers in Jellybean - Nexus

We have a strange bug in our sencha 1.1 app: We have a screen where the user can change date with a date picker. So far so good. We already have this screen since a long time in our app, but now we have a problem on android 4.1 or rather the galaxy nexus: the date picker is not fully rendered and because of that the functionality of the picker is broken. We can't scroll the values in the picker.The strange thing is on our other android devices, emulators (including 4.1.1 - Jellybean) and the iPhone it works without any problems, and in the browser it works also.Did anyone had a similar problem and can help ?